The present invention relates to electrical distribution networks and more particularly to electrical distribution networks which comprise a number of generators and electrical load elements in order to ensure desired operation.
It will be appreciated that electrical distribution networks typically comprise bus bars and grid cables connecting a number of electrical generator sources and electrical loads. Thus, network operators in order to achieve safe operation will determine minimum and maximum fault levels allowable in the electrical system. It will be appreciated each electrical power generator will provide a certain level of electrical current such that if there is a fault in terms of discharge to earth, the appropriate safety mechanisms must be sufficient to accommodate such a discharge surge.
Typically, electrical distribution network operators will determine fault current levels at various network locations by reviewing each electrical generator in terms of feed capability as well as other local sources of electrical power generation, the impedance between the electrical power generator sources and any potential fault and the impedance and nature of the potential faults themselves. The magnitude of determined electrical fault currents provides an electrical current setting for protection devices in rating of circuit breakers and other electrical current carrying equipment. Typically, in order to determine a fault current level on the network the following information is required:                a) network topography (status of all network switches)        b) prospective fault current contribution for all connected generators        c) in feed levels for higher voltage electrical distribution network connection points        d) in feed from devices such as induction motors which when switched off will contribute to electrical current for a time period and which is unpredictable in accordance with use of the respective motor.        
With the above information a power system simulation exercise will be conducted in order to determine fault levels at all locations in the network.